Emulsification dispersants, a method for emulsification and dispersion using the emulsification dispersants, emulsions, and emulsion fuels

ABSTRACT

An emulsifying dispersant includes, as the main component, vesicles formed from an amphiphilic substance capable of self-assembly or an emulsifying dispersant comprising single particles of a biopolymer as the main component. The particles made from amphiphilic substances capable of self-assembly are used. The amphiphilic substances are selected from among polyoxyethylene-hydrogenated castor oil derivatives wherein the average number of added ethylene oxide molecule is 5 to 15, dialkyldimethyl-ammonium halides wherein the chain length of the alkyl or alkenyl is 8 to 22, and phospholipids or phospholipid derivatives. According to the invention a three-phase structure composed of an aqueous phase, an emulsifying dispersant phase and an oil phase is formed on the surface of an emulsion to give an emulsion (such as emulsion fuel) excellent in thermal stability and long-term stability.

CROSS-REFERENCE TO RELATED APPLICATION

This is a divisional of U.S. application Ser. No. 1/547,625 which is anationalization application under 35 U.S.C. § 371 of PCT/JP05/05795filed on Mar. 29, 2005, claiming priority to JP 2004-110915 filed Apr.5, 2004, JP 2004-254384 filed Sep. 1, 2004, JP2004-257363 filed Sep. 3,2004, JP 2004-327915 filed Nov. 11, 2004, JP 2005-024792 filed Feb. 1,2005, JP 2005-024794 filed Feb. 1, 2005, JP 2005-091080 filed Mar. 28,2005 and JP 2005-091081 filed Mar. 28, 2005, the contents of which areincorporated herein by reference in their entirety.

TECHNICAL FIELD

The present invention relates to emulsification dispersants withexcellent long term stability regardless of the type of substance to beemulsified, and a method for emulsification and dispersion using theemulsification dispersants, emulsions, and emulsion fuels.

BACKGROUND ART

Conventionally, the emulsification and dispersion of functional oilbased agents or functional granules into water were conducted byselecting a surfactant according to the required HLB of the functionaloil based agents or properties of granule surface. In addition, therequired HLB value of the surfactant used as an emulsifier had to bechosen distinctively according to whether 0/W type emulsions or W/O typeemulsions were to be formed; moreover, the thermal stability and thelong term stability were not sufficient, and therefore, variousdifferent types of surfactants also had to be used. (ref. Non-patentdocument 1-4).

Furthermore, conventionally, in exhaust gases from thermal engines(automobiles, power generators, ships, air planes, etc.) using lightoil, etc. as fuel, there have been problems involving the inevitablegeneration of CO or NOx, in addition to PM (carbon particulates) or VOC(α-Biphenyl, etc.). For this reason, independent municipalities have setregulation standards (e.g. below 100-110 ppm), and it has been reportedthat emulsion fuels to which 50 wt % water has been added are capable ofserving as a technical solution to this problem (Non-patent document 5,Non-patent document 6, etc.). Moreover, it is known that high viscosityheavy oils, such as distillation residue oils (tar, pitch, asphalt,etc.), oil sand, natural bitumens, orinoco tar, etc., cannot be used atnormal temperature, but can be conditioned for fluidity by the additionof low viscosity petroleum fractions, etc., and the conditioned heavyoils can then be emulsified using a surfactant (Patent document 7).

-   Non-patent document 1: “Emulsion Science” edited by P. Sherman,    Academic Press Inc. (1969)-   Non-patent document 2: “Microemulsions-Theory and Practice” edited    by Leon M. Price, Academic Press Inc. (1977)-   Non-patent document 3: “A technique of Emulsification and    Solubilization” by Atsushi, Tuji, Kougakutosho Ltd. (1976)-   Non-patent document 4: “Development Technique for Functional    Surfactants” CMC Publishing Co., Ltd. (1998)-   Non-patent document 5: “A Reduction Effect of NOx and Graphite in    the Exhaust Gases Generated from Water Emulsified Fuels” searched on    Aug. 25, 2004 The internet URL:    http://www.naro.affrc.go.jp/top/seika/2002/kanto/kan019.html-   Non-patent document 6: “Application study of Water Emulsified Fuel    on Diesel Engine” searched on Aug. 25, 2004 The internet URL:    http://www.khi.co.jp/tech/nj132g05.htm Kawasaki Heavy Industries,    Ltd. Kawasaki Technical Review No. 132-   Patent document 7: Japanese Unexamined Patent Application    Publication No. 07-70574

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, surfactants are not very biodegradable and produce a gas, thuscausing serious problems of environmental pollution. Furthermore,although physicochemical emulsification methods such as the HLB method,phase inversion emulsification method, phase inversion temperatureemulsification method, gel emulsification method, etc., have generallybeen used as conditioning methods for emulsified preparations offunctional oil-based agents, in each case, because an action tothermodynamically stabilize the system by reducing the surface energy ofthe oil/water is the base of the emulsification conditioning process,the emulsification method was therefore accompanied by extremelycomplicated and extensive effort to select the most suitable emulsifier,and in any case, when a variety of oils had been mixed together, it wasalmost impossible for these oils to be stably emulsified.

Furthermore, fuels such as light oil, etc., are mixtures of a variety ofhydrocarbon oils; therefore it is difficult to emulsify water-addedfuels with conventional surfactants, and emulsion fuels that can bestabilized long term by surfactants have not yet been developed.

Moreover, conditioned heavy oils fluidized by the addition of a lowviscosity petroleum fraction, etc. have not been widely used due tosedimentation and deposits in the transportation lines, or due to theenvironmental pollution resulting from incomplete combustion. Inaddition, the emulsion fuels, for which the conditioned heavy oils havebeen emulsified by surfactants, vary in composition and a satisfactorystability has not yet been achieved, even with the use of a largevariety of surfactants.

Hence, the objective of the present invention is to createemulsification and dispersion systems with excellent thermal stabilityand long term stability for the surface of the functional oil-basedagents/water or the functional granules/water, and to provideemulsification dispersants that permit emulsification and dispersionregardless of the Erforderich HLB value of the functional oil basedagents or surface properties of the functional granules, as well as amethod for emulsification and dispersion using the emulsificationdispersants, and emulsions. As an applied example of the emulsions, anadditional objective is to provide emulsion fuels that allow for areduction of environmental effects and that have excellent long termstability.

Means for Solving the Problem

In emulsification methods using conventional surfactants, the basicmethod of emulsification and dispersion was to reduce the surface energyof the oil and water in which the surfactant was absorbed, and a largeamount of emulsifier was required in order to lower the surface tension.In order to do this, the present inventors devised a three-phase methodof emulsification involving the attachment of nanoparticles of anamphiphilic compound existing independently in an oil/amphiphiliccompound/water system onto the surface of the oil-based agent by van derWaals force, and for such emulsification method, the degree of surfacetension of the oil component/water was acknowledged to be crucial forthe attachment of the nanoparticles of the emulsifier. The presentinventors discovered that the emulsions of this three-phase emulsionmethod exhibit extremely high stability compared to the emulsions of thenormal two-phase emulsion method, such as O/W or W/O type emulsions, andas a result, the present invention has been completed based on thesefindings.

That is, for the purpose of accomplishing said objective, emulsificationdispersants related to the present invention are characterized in thatthe main component is vesicles that are formed from amphiphilicsubstances capable of forming vesicles spontaneously and that adhereonto the surface of an oil based material.

Herein, for the vesicles, the preferred average size is 8 nm-500 nm forthe formation of emulsions, and 200 nm to 800 nm when the dispersant isbeing conditioned within a concentration range of 5 to 20 wt % in thedispersion. Additionally, for the amphiphilic substances withself-assembly capabilities as described above, it is preferable to adoptderivatives represented by the following general formula (Formula 1),wherein the average number of added ethylene oxide molecules (E) isbetween 5 and 15 among polyoxyethylene-hydrogenated caster oilderivatives, or those represented by the general formula (Formula 2),including halides of dialkylammonium derivatives, trialkylammoniumderivatives, tetraalkylammonium derivatives, dialkenylammoniumderivatives, trialkenylammonium derivatives, or tetraalkeylammoniumderivatives. In addition, phospholipids or particles made fromphospholipid derivatives may also be used.

Herein, as for the polyoxyethylene-hydrogenated caster oil derivatives,ionic surfactants may be further added within the range of the molfraction 0.1≤Xs≤0.33, and the vesicles may be ionized (cationized oranionized).

For an emulsification dispersion method using the emulsificationdispersant described above, it is preferable to have the oil componentsemulsified and said emulsification dispersant mixed by a ratio of 1 to1000.

Furthermore, in order to accomplish said objective, the dispersants usedin the present invention may be those containing as a main component abiopolymer disintegrated into single particles.

Herein, as for the biopolymers, microbially produced polysaccharides,phospholipids and polyesters, naturally-derived polysaccharides, such asstarch, and one or more than two selected from a family of chitosans maybe considered. For example, as the microbially produced polysaccharides,provided for example are those produced by microorganisms comprisingseveral sugars among the monosaccharides, such as ribose, xylose,rhamnose, fructose, glucose, mannose, glucuronic acid, and gluconicacid, as the structural elements. Some microorganisms that producepolysaccharides with these particular structures are known; however, anypolysaccharide or mixture of such may be acceptable.

Furthermore, examples of the naturally-derived starches include, but arenot limited to, potatoes, glutinous rice powder, tapioca powder, andkelp powder, etc., and a simple substance or compound structure withamphiphilic properties may also be acceptable.

For the emulsification dispersion method using the emulsificationdispersant described above, it is preferable to have the oil componentemulsified and said emulsification dispersant mixed by a ratio of 50 to2000.

In addition, a preferable method for producing the emulsificationdispersant described above is to include a process of forming vesiclesthat are formed from amphiphilic substances capable of forming vesiclesspontaneously, or a process of disintegrating the amphiphilic substancecapable of self-assembly into single particles, and processing theamphiphilic substance that has been either dispersed into vesicles ordisintegrated into single particles into fine particles by adding towater of the designated temperature. The forming process for formingvesicles that are formed from amphiphilic substances capable of formingvesicles spontaneously, and the disintegrating process into singleparticles requires various ingenuities depending on the materials used,but using caster oil derivatives, it is achievable by addition intowater below 60° C. while stirring.

As for the emulsions obtained by mixing said emulsification dispersantwith the oil/fat, an emulsification dispersant phase will be formed onthe interface of the oil and water, thus they are unlikely to mergetogether, regardless of the type of oil/fat used, and the thermalstability and long term stability will be excellent.

Emulsion fuels are provided as examples of such emulsions. The emulsionfuels are characterized in that water added fuels contain as anessential component an emulsification dispersant comprised of vesiclesthat are formed from amphiphilic substances capable of forming vesiclesspontaneously and that adhere onto the surface of the oil basedmaterial, and wherein the average particle size of said vesicles is 8 nmto 500 nm when the emulsion is being formed, and 200 nm to 800 nm whenthe dispersant is being regulated within a concentration range of 5 to20 wt % in the dispersion.

Herein, light oil, heavy oil (Heavy oil A, Heavy oil C), petroleum,gasoline, etc, or viscosity-conditioned high viscosity heavy oils(distillation residue oil, oil sand, natural bitumens, orinoco tar,etc.) are assumed as the fuel, whereas for the amphiphilic substancecapable of self-assembly, among the polyoxyethylene-hydrogenated castoroil derivatives represented by the following general formula (Formula3), derivatives with an average number of 5 to 15 added ethylene oxidemolecules are preferable for use.

In order to maintain the CO or NOx value of the combustion gasesaccording to said regulation standards, the preferred compositionconsists of an amphiphilic substance at 0.1 to 15.0 wt %, said fuel at 1to 95 wt %, and the corresponding proportion of water according to theweight ratio.

If heavy oil A is used as the fuel, and among said derivatives, if aderivative (HCO-10) with an average number of 10 added ethylene oxidemolecules is used as the amphiphilic substance, the recommendedcomposition consists of HCO-10 at 0.1 to 14.25 wt %, heavy oil A at 5 to95 wt %, and the corresponding proportion of water, and more preferably,a composition of HCO-10 at 5 to 14.25 wt %, heavy oil A at 5 to 50 wt %and the corresponding proportion of water is recommended.

If light oil is used as the fuel, and said HCO-10 is used as theamphiphilic substance, a composition consisting of HCO-10 at 0.4 to 10wt %, light oil at 5 to 95 wt %, and the corresponding proportion ofwater, and more preferably, a composition consisting of HCO-10 at 0.8 to10 wt %, light oil at 5 to 60 wt % and the corresponding proportion ofwater is recommended.

Furthermore, if heavy oil is used as the fuel, and said HCO-10 is usedas the amphiphilic substance after undergoing a fluidization processwith a viscosity-conditioning agent, a composition consisting of HCO-10at 0.3 to 9 wt %, conditioned heavy oil at 80 to 10 wt % and thecorresponding proportion of water, and more preferably, a compositionconsisting of HCO-10 at 0.3 to 9 wt %, conditioned heavy oil at 70 to 30wt % and the corresponding proportion of water is recommended.

Additives such as anticorrosives, flame-retardant agents, andantiseptics, etc., may be arbitrarily mixed into said emulsion fuelsdepending on the purpose. Said three-phase emulsification technique maybe applied to the mixed oils with synthetic oils, vegetable oils, etc.,other than light or heavy oils.

Additionally, the preferred method for producing emulsification fuelsdescribed above includes a process for conditioning the fluidity ofcrude oils, a process for adjusting the temperature of thefluidity-conditioned crude to at or below the designated temperature,and a process for processing the crude oil of which the temperature wasadjusted by said temperature adjustment process into fine particles byadding it dropwise into said emulsification dispersant liquid.Particularly for heavy oils, temperature control is important. Afterheating to approximately 80° C. to allow for fluidization of the heavyoil, the designated amount of viscosity-conditioned oil is added forhomogenization. The viscosity therein may be controllable in accordancewith the amount of the viscosity-regulated oil. However, when mixed withan emulsification dispersant, it is necessary to reduce the temperatureto approximately 60° C. As described above, the gradually addition of asmall amount of such viscosity-conditioned heavy oil or light oil, etc.into water and an emulsification dispersant for an emulsion fuelcomposition, after having been stirred, results in the formation of anemulsion fuel.

Effects of the Invention

As described, the use of emulsification dispersants related to thepresent invention permits the formation of functional oil basedagents/water or functional granules/water emulsion systems withexcellent thermal and long term stability. With conventionalhydrocarbon-related surfactants, it was difficult to form stableemulsions; however, the use of emulsification dispersants in the presentinvention makes it possible to stabilize emulsions for a long period oftime in a wide range of temperature regions.

Furthermore, with the use of one kind of emulsification dispersant, theemulsification and dispersion of an oil/fat component becomes possibleregardless of the required HLB value of the oil agent to be emulsifiedor the surface properties of the functional granules, and therefore,emulsifications of hydrocarbon-based oil agents or silicone-based oilagents also becomes possible. This minimizes the complexity and effortsin selecting an emulsifier, and also allows for emulsification of avariety of mixed oils at the same time.

Moreover, the concentration of the emulsification dispersant requiredfor an emulsification is only 1/10 to 1/1000 of conventionalsurfactants, thus significantly reducing the effect on the environment.

Furthermore, as for the fuel emulsions involved in the presentinvention, water-added light oil or heavy oil was prepared so as tocontain an emulsification dispersant as an essential component mainlycomprised of vesicles that are formed from amphiphilic substancescapable of forming vesicles spontaneously and that adhere onto thesurface of an oil based material; therefore, fuel emulsions withextremely excellent long term stability were formed, and moreover, thegenerated concentrations of NOx, CO, and HC (hydrocarbons) in exhaustgas are also reduced.

Through the use of the emulsion fuels of the present invention, longerlife-spans of combustion engines may also be expected. In addition,through the use of the emulsion fuels of the present invention, agreater amount of CO₂ is generated than would be expected from theweight ratio of the fuel components, and the oxygen concentration isincreased, thus achieving complete combustion while reducing the carbonparticulates (PM) generated from incomplete combustion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B illustrate an emulsification mechanism, of which FIG. 1Ais a diagram illustrating an adsorption mechanism of a monomolecularfilm of a conventional surfactant, and FIG. 1B is a diagram illustratingan adherence mechanism of nanoparticles.

FIG. 2A is a diagram illustrating phenomena caused by a thermalcollision with surfactant molecules of conventional adsorption type, andFIG. 2B is a diagram illustrating phenomena caused by a thermalcollision with vesicles of emulsifier phase adherence type.

FIG. 3 is a TEM photograph of DMPC-C14TAB emulsifier particles (Xs=0.5,equimolar mixture).

FIG. 4 is a distribution of scattering strength and TEM photographs ofDMPC-C14TAB emulsifier particles with an average particle size of 390.0nm (A) and 2097.8 nm (B).

FIG. 5 is a figure showing observation results of an XRD peak of anemulsification by adding oil into 0.5 wt % of DMCP-C14TAB liquidcrystals mixed with water.

FIG. 6 is a block diagram describing a manufacturing method for anemulsification dispersant.

FIG. 7 illustrates patterns of differences in the emulsified statesaccording to the oil content.

FIG. 8 is a block diagram that illustrates a manufacturing method for anemulsion fuel.

FIG. 9A is a photograph showing a state of an emulsion that has beenleft for two days after conditioning a light oil and a heavy oil A usinga conventional surfactant,

FIG. 9B is a photograph showing a state of an emulsion that has beenleft for thirty days after conditioning a light oil and a heavy oil Ausing the three-phase emulsification method.

FIG. 10 is a photograph showing the emulsification state of Table 2.

FIG. 11 is a photograph showing the emulsification state of Table 5.

FIG. 12 is a photograph that showing the emulsification state of Table6.

FIG. 13 shows the results of viscosity conditioning conducted withkerosene, light oil, heavy oil A, and liquid paraffin.

FIG. 14 shows the results of an experiment in which changes inconcentration of each exhaust gas component is measured while shiftingfrom the combustion of a light oil to the combustion of a light oilemulsion.

FIG. 15 shows the results of an experiment in which changes inconcentration of each exhaust gas component is measured while shiftingfrom the combustion of a heavy oil A to the combustion of a heavy oil Aemulsion.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the ideal embodiments of the present invention areexplained.

FIG. 1 conceptually illustrates an emulsification method with aconventional surfactant and the three-phase emulsification methodadopted herein.

In an emulsification method using a conventional surfactant, as shown inFIG. 1A, in the same molecule, the surfactant has both hydrophilic andlipophilic groups, which are different in their nature. As for ahydrophilic emulsifier, the lipophilic groups of the surfactant aredissolved into the oil, while the hydrophilic groups are aligned outsidethe oil particle, thus the oil particle is likely to have affinity towater and mixed homogeneously in the aqueous medium to produce an O/Wtype emulsion. Whereas, for a lipophilic surfactant, the hydrophilicgroups of the surfactant are oriented toward the water particles, whilethe lipophilic groups are aligned outside of the water particle, thusthe water particle is likely to have affinity to the oil and mixedhomogeneously in the oil medium to produce a W/O type emulsions.

However, with such conventional emulsification method, the surfactant isadsorbed on the oil surface, forming an emulsified monomolecular film,and it is inconvenient that surface properties change depending on thetype of the surfactant. Moreover, as shown in FIG. 2A, due to thecoalescence caused by thermal collisions of the oil drops, the size ofthe oil drops gradually become larger, and finally, a separation of theoil and the surfactant aqueous solution takes place. In order to preventthis, it is necessary to form microemulsions for which a large amount ofa surfactant must be used, and therefore is inconvenient.

In the present invention, as shown in FIG. 1B, nanoparticles of anemulsifier phase attach to the oil or water particles, creating athree-phase structure consisting of aqueous phase-emulsificationdispersant phase-oil phase, without lowering the surface energy andwithout any mutual solubility at interface, unlike conventionalsurfactants, and long term stability of an emulsion can be achieved bypreventing the coalescence caused by thermal collisions as shown in FIG.2B. Furthermore, based on such a mechanism, the method adopts a newemulsification method (three-phase emulsification method) that allowsfor the formation of emulsions using only a small amount ofemulsification dispersant.

As for the emulsification dispersant, in order to realize suchthree-phase emulsification, an emulsification dispersant mainlycomprised of vesicles that are formed from amphiphilic substancescapable of forming vesicles spontaneously and that adhere onto thesurface of an oil based material, or an emulsification dispersant mainlycomprised of a biopolymer disintegrated into single particles have bothbeen considered.

The preferred average particle size of the vesicles formed from anamphiphilic substance is between 8 nm and 500 nm. A particle sizesmaller than 8 nm reduces the suction action attributed to the Van derWaals force, thereby impeding the vesicles from adhering onto thesurface of the oil drops; however, if the particle size is larger than500 nm, stable emulsions will not be maintained. In FIG. 3, a TEMphotograph is shown representing a particle size of 8 nm. Moreover, ifthe particle size is larger than 500 nm when the emulsion is beingformed, needle-shaped particles will be generated, and therefore, stableemulsions will not be maintained. In FIG. 4, distributions of scatteringstrength and TEM photographs of an average particle size of 390.0 nm(smaller than 500 nm: (A) in the figure) and of an average particle sizeof 2097.8 nm (larger than 500 nm: (B) in the figure) are shown.

In order to maintain the particle size of the vesicles within this rangewhile an emulsion is formed, a range of 200 nm to 800 nm when thedispersant is being conditioned within a concentration range of 5 to 20wt % in the dispersion is acceptable for conditioning of the dispersant.This is due to the fact that vesicles are processed into fine particlesduring the emulsion formation process. By observing the XRD peak in FIG.5, it is confirmed that the vesicles have not been destroyed in thisprocess. In the figure, X_(H) represents the mol fraction of the oilphase to the emulsifier.

For the amphiphilic substances forming such vesicles, it is preferableto adopt polyoxyethylene-hydrogenated caster oil derivatives representedby the following general formula (Formula 4), or dialkylammoniumderivatives represented by the general formula (Formula 5), includinghalides of trialkylammonium derivatives, tetraalkylammonium derivatives,dialkenylammonium derivatives, trialkenylammonium derivatives, ortetraalkeylammonium derivatives.

As for the polyoxyethylene-hydrogenated caster oil derivatives,derivatives with an average number of 5 to 15 added ethylene oxidemolecules (E) may be used. An example wherein the average number ofadded ethylene oxide molecules has been changed from 5 to 20 is shown inTable 1. The range between 5 and 15 is stable; however, at 20, anemulsion formation is possible for a few days, but the stability cannotbe maintained. In order to enhance the adhering strength, the vesiclesto be obtained may be ionized. In forming such ionized vesicles as ionicsurfactants, for the cationization, the use of alkyl oralkenyltrimethylammonium salt (with a carbon chain length of 2 to 22),preferably hexadecyltrimethylammonium bromide (hereinafter called CTAB),wherein the carbon chain length is 16, for the anionization,alkylsulphate (CnSO₄ ⁻M⁺ with a carbon chain length of 8 to 22, M:alkali metals, alkaline earth, ammonium salt, etc.) is recommended. Asfor the method of ionization, for example, mix HCO-10 and CTAB with anethanol solvent, remove the ethanol to form a mixture of HCO10 and CTAB,and then, add distilled water into the mixture so that HCO-10 becomes 10wt %, and stir to incubate in a temperature-controlled container. In themixed vesicles of HCO-10 and CTAB, if the CTAB mol fraction (Xs) isXs≤0.1, coherent cationic properties of the mixed vesicles cannot bemaintained, while if it is 0.33≤Xs, stable mixed vesicles cannot beobtained, and thus, a range of 0.1≤Xs≤0.33 is preferred for thecationization.

TABLE 1 An example of heavy oil A emulsification with HCO-5. No. 1 2 3 45 HCO-5 2 2 2 2 2 Water 78 58 38 18 8 Heavy oil A 20 40 60 80 90Emulsification stability ◯ ◯ Δ Δ Δ (After 1 day) Emulsificationstability ◯ Δ Δ Δ Δ (After 7 days) Emulsified state W/O type emulsion Anexample of heavy oil A emulsification with HCO-15. No. 1 2 3 4 5 HCO-5 22 2 2 2 Water 78 58 38 18 8 Heavy oil A 20 40 60 80 90 Emulsificationstability ◯ ◯ ◯ ◯ ◯ (After 1 day) Emulsification stability ◯ ◯ ◯ Δ Δ(After 7 days) Emulsified state O/W type W/O type emulsion emulsion Anexample of heavy oil A emulsification with HCO-20. No. 1 2 3 4 5 HCO-5 22 2 2 2 Water 78 58 38 18 8 Heavy oil A 20 40 60 80 90 Emulsificationstability Δ Δ X X X (After 1 day) Emulsification stability X X X X X(After 7 days) Emulsified state O/W type W/O type emulsion emulsion ◯:No phase separation, Δ: Separated due to difference in specific gravity(coacervation), X: Separated Figures are shown in weight %

Furthermore, as for the amphiphilic substance that forms the vesicles,phospholipids or phospholipids derivatives, etc. may be used. For thephospholipids, among structures represented by the following generalformula (Formula 6), DLPC with a carbon chain length of 12(1,2-Dilauroyl-sn-glycero-3-phospho-rac-1-choline), DMPC with a carbonchain length of 14 (1,2-Dimyristoyl-sn-glycero-3-phospho-rac-1-choline)and DPPC with a carbon chain length of 16(1,2-Dialmitoyl-sn-glycero-3-phospho-rac-1-choline) may be used.

Additionally, among structures represented by the following generalformula (Formula 7), DLPG with a carbon chain length of 12(1,2-Dilauroyl-sn-glycero-3-phospho-rac-1-glycerol) Na salt or NH₄ salt,DMPG with a carbon chain length of 14(1,2-Dimyristoyl-sn-glycero-3-phospho-rac-1-glycerol) Na salt or NH₄salt, or DPPG (1,2-Dipalmitoyl-sn-glycero-3-phospho-rac-1-glycerol) Nasalt or NH₄ salt may also be used.

Furthermore, egg yolk lecithin or soybean lecithin may be used asphospholipids. Moreover, for the emulsification and dispersion of an oilcomponent using an emulsification dispersant comprising said vesicles,it is recommended to have the oil component emulsified and saidemulsification dispersant mixed with said oil component by a weightratio of 4 to 200.

On the other hand, for biopolymers, provided for example are microbiallyproduced biopolymers comprising as structure elements some sugars amongthe monosaccharides, such as ribose, xylose, rhamnose, fructose,glucose, mannose, glucuronic acid, and gluconic acid, etc. As formicroorganisms that produce polysaccharides with these particularstructures, alcaligenes, xanthomonas, arthrobacter, bacillus, hansenula,and brunaria are known, and any polysaccharide or mixture of such may beused. Gelatin or blockcopolymers may also be used in place of abiopolymer.

When emulsifying and dispersing an oil component using an emulsificationdispersant comprising as the main component a biopolymer disintegratedinto single particles, it is recommended that the oil component isemulsified and said emulsification dispersant mixed with said oilcomponent by a weight ratio of 50 to 2000.

A method of producing the emulsification dispersant described aboverequires a process for dispersing an amphiphilic substance capable ofself-assembly into vesicles (vesiclization), or a process fordisintegrating into single particles (step I). This requires variousingenuities depending on the material used, however, as shown in FIG. 6,a process of water-dispersing or water-swelling the amphiphilicsubstance (step I-1), a process of thermally adjusting the temperatureto approx. 80° C. (step I-2), a process of adding a denaturant such asurea to destroy the hydrogen bond (step I-3), a process of conditioningthe pH to below 5 (step I-4), any of such processes, or a combination ofwhich may achieve disintegration into single particles, orvesiclization. Particularly with caster oil derivatives, disintegrationis achievable by adding the caster oil derivative dropwise into waterbelow 60° C. while stirring.

After a process for conditioning the designated concentration byaddition into water below the designated temperature (below 60° C.)(step II), and a process for stirring to process the particles into fineparticles (step III), an emulsification dispersant is produced. As forthe stirring, stirring at a high speed (up to 16000 rpm, in lab.) ispreferred; however, when using a stirring device, stirring at up toapproximately 1,200 rpm will allow for processing in fewer minutes. Inaddition, it is preferable to perform the process of adding into thewater and the process of processing the particles into fine particles atthe same time. Biopolymers, etc. require a complicated process, sincethe network structures must be destroyed in order to disintegrate intosingle particles; however, these processes are individually describedfor each embodiment (embodiment 6, embodiment 8, embodiment 9, andembodiment 10).

Hereinafter, several embodiments of emulsification dispersantscomprising as the main component vesicles formed from amphiphilicsubstances, and embodiments of emulsification dispersants comprising asa main component of biopolymers disintegrated into single particles aredescribed.

Embodiment 1

(An Embodiment Wherein Vesicles from Hydrogenated Caster Oil are Used asan Emulsification Dispersant)

As the vesicles from hydrogenated caster oil, amongpolyoxyethylene-hydrogenated caster oil derivatives, a derivative withan average number of 10 added ethylene oxide (EO) molecules (E) (fromhereon HCO-10; molecular weight 1380 g/mol) is used.

It is known that the HCO-10 is hardly soluble in water and formsvesicles by assembling themselves in water (Ref “Regarding a Formationof Vesicles of Non-ionic Surfactant Related to Poly(oxyethylene)Hydrogenated Caster Oil” Journal of Japan Oil Chemist's Society, vol.41, No. 12, P. 1191-1196, (1992), “Thermal Properties ofPoly(oxyethylene) Hydrogenated Caster Oil Vesicle Dispersant Solution”Japan Oil Chemist's Society, vol. 41, No. 12, P 1197-1202, (1992)), asshown in Table 2, although the average particle size depends on theconcentration; however, at the stage of aqueous dispersion the particlesize is 200 nm to 800 nm. Considering the stability of the dispersion,the size was set in the range of 5 to 20 wt %.

TABLE 2 Average particle size at various concentration of HCO-10.Average Second most Concentration particle Most distributed distributed(wt %) size/nm particle size/nm particle size/nm 1 243.17 88.43 3 321.13205.63 6 440.8 449.67 136.47 7 443.33 160.7 8 473.33 136.1 9 513.3 92.73256.2 10 760.5 37.7 313.8 15 775 64.73 415.3 20 735.57 41.5 192.8

For the purpose of investigating an equivalent or better emulsificationcapability compared to conventional surfactants using suchemulsification dispersant, a system of heavy oil A and water was usedwherein the concentration of HCO-10 to water was set at 10 wt %, forwhich regular tap water was used for the water, and where theemulsification was conducted in room temperature by stirring forapproximately five minutes at 8000 rpm using a homomixer. The emulsifiedstate was examined by changing the weight ratio of the heavy oil A. Theproportion of each composition of the hydrogenated caster oil(HCO-10)-water-heavy oil A, and the result of the emulsified state ofthe emulsions are shown in Table 3.

TABLE 3 Example (1) of emulsification with HCO-10. No. 1 2 3 4 5 6 7 8 910 HCO-10 9 8 7 6 5 4 3 2 1 0.5 Water 81 72 63 54 45 36 27 18 9 4.5Heavy oil A 10 20 30 40 50 60 70 80 90 95 Emulsification ◯ ◯ ◯ ◯ ◯ Δ Δ XX X stability (1 month/room temperature) Emulsified (1) (2) (3) state ◯:No phase separation, Δ: Separated due to difference in specific gravity(coacervation), X: Separated (1): O/W type emulsion, (2): W/O typeemulsion, (3): W/O microemulsion and separated aqueous phase Figures areshown in weight %.

As shown by these results, with a small amount of HCO-10, it waspossible to emulsify up to 70 wt % of the heavy oil A. As shown in FIG.7, in which the pattern changes of the emulsified states are shown afterchanging the proportion of the heavy oil A and the water, by increasingthe proportion of the heavy oil A to water, from a diluted O/W typeemulsion state (a) to a thick O/W type emulsion state, and after passinga transient state (c), then reaching a deposit W/O type emulsion state(d), when the proportion of the heavy oil A is exceeded, the reversemicro-emulsion state of (e) and a separate aqueous phase was formed.Said No. 1 to No. 5 are states of either (a) or (b), No. 6 and No. 7 arestates of (d), and No. 8 through No. 10 correspond to states of (e). Inaddition, a characteristic of the invention was that in No. 6 and 7,apparently partial coacervation (creaming) was observed, which wasredispersed by stirring moderately. However unlike the creaming stateobtained by the conventional surfactant, a coalescence of oil drops wasnot observed, even after having been left to sit for an extended periodof time.

Embodiment 2

For the purpose of examining the emulsified state of HCO-10 in a systemof various types of oil agents, such as liquid paraffin and water, theconcentration of the HCO-10, the emulsification dispersant of the water,and the concentration of the entire system were fixed as 10 wt % and 7wt %, respectively, for which regular tap water was used for the water,and the emulsified state per each oil agent was examined after stirringfor approximately five minutes by a normal stirrer at room temperature,thereby obtaining the results shown in Table 4.

TABLE 4 Emulsification example (2) with HCO-10 Emulsification stability(1 month/room Emulsified Oil type HCO-10 Water temperature) state Liquidparaffin 7 63 ◯ O/W type Olive oil 7 63 ◯ O/W type Silicone (2 cSt) 7 63◯ O/W type Silicone (5 cSt) 7 63 ◯ O/W type Silicone (100 cSt) 7 63 ◯O/W type Isopropyl myristate 7 63 ◯ O/W type Hexadecane 7 63 ◯ O/W typeLimonene 7 63 ◯ O/W type Tocopherol 7 63 ◯ O/W type (Vitamin E) Figuresare shown in wt %. Oil content is 30 wt %.

As seen from these result, a favorable emulsified state was obtainedregardless of the type of oil agent. Moreover, since this emulsifiedstate did not change even after having been left to incubate at roomtemperature for one month, excellent emulsions were obtained.

Embodiment 3

(An Embodiment Wherein Distearyldimethylammoniumchloride is Used as theEmulsification Dispersant)

Next, an embodiment wherein distearyldimethylammoniumchloride is used asan emulsification dispersant is described. The emulsified state ofliquid paraffin using this emulsification dispersant was examined, andthe results are shown in Table 5. With approximately 0.5 wt % or over, afavorable state was obtained. Furthermore, even with silicone oil, afavorable state was obtained as shown in Table 6.

TABLE 5 No. 1 2 3 Emulsifier 0.5 2.5 5 Water 49.5 47.5 45 Liquidparaffin 50 50 50 Emulsified state O/W type O/W type O/W typeEmulsification stability Δ ◯ ◯ (1 month/room temperature) ◯: No phaseseparation, Δ: Separated due to difference in specific gravity(coacervation), X: Separated Figures are shown in wt %.

TABLE 6 Emulsifier 3.1 Water 59 Silicone oil (2 cs) 37.9 Emulsifiedstate O/W type Emulsification stability ◯ (1 month/room temperature) ◯:No phase separation Figures are shown in wt %.

Embodiment 4

(An Embodiment Wherein Phospholipids are Used as the EmulsificationDispersant)

Next, an embodiment wherein phospholipids are used as the emulsificationdispersant is described.

The emulsified state when using said phospholipids (DMPC, DMPG, DPPC)was examined by changing the type of oil agents as shown in Table 7.With each oil agent, the oil composition was set within a range of 0.1to 35 wt %, and regular tap water was used for the water, where a normalstirrer was used for the five minutes stirring at a room temperature.Furthermore, the concentration of the phospholipids was set in a rangeof 0.005 to 0.5 wt %.

TABLE 7 Emulsification Stability (1 month/room Emulsified Oil typePhospholipids Water temperature) state Liquid paraffin 0.005-0.5 64.5-99◯ O/W type Olive oil 0.005-0.5 64.5-99 ◯ O/W type Silicone (2 cSt)0.005-0.5 64.5-99 ◯ O/W type Silicone (5 cSt) 0.005-0.5 64.5-99 ◯ O/Wtype Silicone 0.005-0.5 64.5-99 ◯ O/W type (100 cSt) Octan 0.005-0.564.5-99 ◯ O/W type Decane 0.005-0.5 64.5-99 ◯ O/W type Dodecane0.005-0.5 64.5-99 ◯ O/W type Tetradecane 0.005-0.5 64.5-99 ◯ O/W typeHexadecane 0.005-0.5 64.5-99 ◯ O/W type Octadecane 0.005-0.5 64.5-99 ◯O/W type Benzene 0.005-0.5 64.5-99 ◯ O/W type Nonylbenzene 0.005-0.564.5-99 ◯ O/W type Limonene 0.005-0.5 64.5-99 ◯ O/W type Tocopherol0.005-0.5 64.5-99 ◯ O/W type (Vitamin E) Figures are shown in wt %. Oilcontent is 0.1-35 wt %.

From these results, in emulsifications using phospholipids (DMPC, DMPG,and DPPC), favorable emulsified states were also obtained with a smallamount of phospholipids, regardless of the type of oil agent. Moreover,the obtained emulsions had excellent thermal and long term stabilitywith no changes in the emulsified state after having been left toincubate at room temperature for one month.

Embodiment 5

In addition, egg yolk lecithin was used as a phospholipid, and theemulsified state was examined for egg yolk lecithin and silicone oil,and egg yolk lecithin and hexadecane. The results are shown in Table 8.In the Table, the case of (1) is an embodiment wherein the egg yolklecithin had been hydrogenated, and (2) is an embodiment wherein the eggyolk lecithin had not been hydrogenated. Also in these case, emulsionswith excellent thermal and long term stability were obtained.

TABLE 8 Emulsification stability (1 month/ Phospho- Amount roomEmulsified Oil type lipids of oil Water temperature) state Silicone (1)0.3 33.8 65.9 ◯ O/W type (2 cSt) Hexadecane (2) 0.9 33 66.1 ◯ O/W typeFigures are shown in wt %.

Embodiment 6

(An Embodiment Wherein a Biopolymer Disintegrated into Single Particlesis Used as the Emulsification Dispersant)

Next, an embodiment in shown in which the emulsification dispersantcomprises as a main component a biopolymer disintegrated into singleparticles

For the biopolymer, among the microbially produced biopolymers describedpreviously, a polysaccharide produced by alcaligenes was used. Thepolysaccharide forms a network structure when dispersed in water andbecomes a viscous liquid; therefore, the network structure must bedisintegrated into single particles. Then, the biopolymer aqueoussolution, wherein the powder of the biopolymer was dispersed into acertain amount of water, was left all the day so as to make it swell,and then thermally adjusted for thirty minutes at 80° C., into whichurea was added to destroy the hydrogen bonds of the biopolymer so as todisintegrate into single particles. It was possible to disintegrate abiopolymer of up to 0.1 wt % into single particles using an urea aqueoussolution of 4 mol/dm³.

In order to examine whether an aqueous dispersion of a biopolymerdisintegrated into single particles has the same emulsificationcapability with oil agents as conventional surfactants, a liquidparaffin that is one of the hydrocarbon oils was used to examine theemulsification capability according to the dispersion concentration ofthe biopolymer as shown in Table 9, whereby it was possible to emulsifyup to 70 wt % (water 30 wt %) for the concentration of liquid paraffinwith aqueous dispersions of 0.05 wt % biopolymer. Moreover, the state ofthe emulsion did not show any changes elapsed after preparation and wasextremely stable. In addition, when the biopolymer was set to be 0.04 wt% and the liquid paraffin to be 30 wt %, the temperature for theemulsification changed within a range of 25° C. to 75° C.; the formedemulsions were stable at any temperature.

TABLE 9 Biopolymer Amount of liquid paraffin (wt %) (wt %) 10 30 50 6070 80 0.01 X X X X X X 0.05 ◯ ◯ ◯ ◯ ◯ X 0.09 ◯ ◯ ◯ ◯ X X

Furthermore, while the concentration of liquid paraffin as an oil agentwas set to be 30 wt %, the biopolymer concentration was changed in orderto examine the emulsification capability of the biopolymer, andemulsification from 0.04 wt % was found to be possible.

Embodiment 7

Next, when the concentration of the biopolymer was set to be 0.04 wt %and the concentration of the oil agent to be 30 wt %, various kind ofoils was changed to examine the effect on the emulsified state of theemulsion. The results are shown in Table 10. The oil agents used herewere hexadecane, silicone, isopropylmyristate, squalane, olive oil,jojoba oil, cetostearyl alcohol, oleyl alcohol, and oleic acid. Thoughemulsion of oleic acid showed separation after several days, emulsion ofthe other oil agents was stable.

TABLE 10 Emulsification stability (1 months/room Emulsified Oil typeBiopolymer Water temperature) state Hexadecane 0.04 69.96 ◯ O/W typeSilicone 0.04 69.96 ◯ O/W type Isopropyl- 0.04 69.96 ◯ O/W typemyristate Squalane 0.04 69.96 ◯ O/W type Olive oil 0.04 69.96 ◯ O/W typeJojoba oil 0.04 69.96 ◯ O/W type Cetostearyl 0.04 69.96 ◯ O/W typealcohol Oleyl alcohol 0.04 69.96 ◯ O/W type Oleic acid 0.005-0.5 64.5-99X O/W type The figures are shown in wt %. Oil content is 30 wt %.

From the above results, it has become apparent that a biopolymer hasexcellent emulsification capability, and even in low concentrations of0.04 wt % the emulsion was stable, which is considered to be due to thesingle particles of the biopolymer adhering around the oil dropletscreating an emulsification dispersant phase, and forming three-phaseemulsion of aqueous phase-emulsification dispersant phase-oil phase.

Embodiment 8

The following example is a case in which naturally-derived starch isused as a biopolymer.

Potato starch, glutinous-rice powder, and tapioca powder (cassava potatopowder) were used as the typical example of starch, and liquid paraffinand hexadecane were used as oil.

When conditioning the emulsifier, in order to disintegrate these starchinto single particles, these starch were dispersed in water and heatedto 90° C. with stirring, and then cooled down to room temperature so asto obtain a favorable dispersion, and from this operation a sugarpolymer dispersion was obtained for use as the emulsifier.Moreover, when conditioning the emulsions at room temperature after theoperation of disintegration into single particles, the emulsions wereconditioned by the addition of an oil phase with stirring as appropriatefor the starch aqueous dispersion. The results are shown in Table 11through Table 13.

TABLE 11 Example (1) for emulsified state using starch. No. 1 2 3 4 5 67 8 9 10 11 Potato starch 0.18 0.16 0.14 0.12 0.1 0.08 0.07 0.06 0.050.04 0.02 Water 89.82 79.84 69.86 59.88 49.9 39.92 34.93 29.94 24.9519.96 9.98 Liquid paraffin 10 20 30 40 50 60 65 70 75 80 90Emulsification stability Δ Δ Δ Δ Δ Δ ◯ ◯ ◯ ∇ X (1 month/roomtemperature) ◯: No phase separation, Δ: Separated due to the differencein specific gravity with the O/W type emulsion (coacervation), ∇:Separated due to the difference in specific gravity with the W/O typeemulsion (coacervation), X: Separation of the W/O type emulsion andwater Figures are shown in wt %

TABLE 12 Example (2) for emulsified state using starch. No. 1 2 3 4 5 67 8 9 Glutinous rice powder 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02starch Water 89.82 79.84 69.86 59.88 49.9 39.92 29.94 19.96 9.98 Liquidparaffin 10 20 30 40 50 60 70 80 90 Emulsification stability Δ Δ Δ Δ ∇ ∇∇ X X (1 month/room temperature) Δ: Separated due to the difference inspecific gravity with the O/W type emulsion (coacervation), ∇: Separateddue to the difference in specific gravity with the W/O type emulsion(coacervation), X: Separation of the W/O type emulsion and water Figuresare shown in wt %

TABLE 13 Example (3) for emulsified state according to different typesof starch. Emulsifier Emulsified Starch type amount Water state Potatostarch powder 0.1 49.9 ◯ Glutinous rice powder 0.1 49.9 ◯ Tapioca powder0.5 49.5 ◯ (cassava potato) Figures are shown in wt % Oil: soybean oil50 wt %

Embodiment 9

(The Following Case is an Example of an Embodiment Wherein Chitosan isUsed as the Biopolymer)

Liquid paraffin was used as the oil.

When conditioning the emulsifier, the chitosan was dispersed in waterand acidified to below pH 5 in order to disintegrate chitosan intosingle particles. This operation apparently led to be transparent andchitosan was disintegrated into single particles, and a favorabledispersion was ultimately obtained. When forming the emulsion by atvarious pHs, pH adjustment was performed after disintegrating intosingle particles.Moreover, when forming the emulsions, after the operation ofdisintegration into single particles, the emulsions were formed byadding an oil phase with stirring suitable for the chitosan dispersion.The results are shown in Table 14. Additionally, the results obtainedafter adjusting the pH to 4, 7, and 10 are shown in Table 15.

TABLE 14 Emulsified state using chitosan. No. 1 2 3 4 5 6 7 8 9 10 11Chitosan 0.45 0.4 0.35 0.3 0.25 0.2 0.175 0.15 0.125 0.1 0.05 Water89.55 79.6 69.65 59.7 49.75 39.8 34.83 29.85 24.88 19.9 9.95 Liquidparaffin 10 20 30 40 50 60 65 70 75 80 90 Emulsification stability(1 Δ ΔΔ Δ Δ Δ ◯ ◯ ◯ ∇ X month/room temperature) ◯: No phase separation, Δ:Separated due to the difference in specific gravity with the O/W typeemulsion (coacervation), ∇: Separated due to the difference in specificgravity with the W/O type emulsion (coacervation), X: Separation of theW/O type emulsion and water Figures are shown in wt %

TABLE 15 Effect of pH on emulsification using chitosan No. 1 2 3 pH 4 710 Emulsified state Δ Δ ◯ ◯: No phase separation, Δ: Separated due tothe difference in specific gravity with O/W type emulsion (coacervation)

Embodiment 10

(The Following Case is an Embodiment Wherein Kelp Powder, aNaturally-Derived Polysaccharide is Used as the Biopolymer)

Fucoidan contained in kelp powder was used as a sugar polymer component.

When conditioning the emulsifier, kelp powder was dispersed in water andacidified to below pH 5 in order to disintegrate fucoidan into singleparticles.

Furthermore, when forming the emulsions after disintegrating into singleparticles, the emulsions were formed by adding an oil phase withstirring suitable for the kelp powder dispersion.

The results are shown in Table 16.

TABLE 16 Emulsified state using kelp powder. No. 1 2 3 4 5 6 7 8 9 Kelppowder 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 Water 89.55 79.6 69.6559.7 49.75 39.8 29.85 19.9 9.95 Liquid paraffin 10 20 30 40 50 60 70 8090 Emulsification stability (1 Δ Δ Δ Δ Δ Δ ∇ ∇ X month/room temperature)Δ: Separated due to the difference in specific gravity with the O/W typeemulsion (coacervation), ∇: Separated due to the difference in specificgravity with the W/O type emulsion (coacervation), X: Separation of theW/O type emulsion and water Figures are shown in wt %

When an emulsification method (three-phase emulsification method) inwhich an emulsification dispersant comprising vesicles formed from anamphiphilic substance or a biopolymer disintegrated into singleparticles is used as the main component is compared to an emulsificationmethod using a conventional surfactant, the following commoncharacteristics were acknowledged.

First, in the conventional emulsification method, a surfactant wasadsorbed onto interface of oil and water, and performed emulsion bylowering the interfacial energy of the oil/water. Secondly, thethree-phase emulsification method is characterized in that anemulsification dispersant phase is constructed as a result of adherenceof nanoparticles onto the interface of oil and water due to van derWaals force, thus permitting an emulsification without changing theinterfacial energy regardless of the required HLB value of an oil basedagent to be emulsified.

As a result, in an emulsification using conventional surfactant,coalescence were induced due to the thermal collision of oil droplets;on the other hand, in case of the three-phase emulsification, since thenanoparticles in the emulsifier phase adhered onto the surface of theoil droplets, even if they collided, coalescence were less likely tooccur, then thermal stability was sustained for long period of time.

Furthermore, in the emulsification using conventional surfactants, theselection of an appropriate surfactant is required in accordance withthe properties of the oil droplets; on the other hand, in thethree-phase emulsification method, once the nanoparticles are selected,the same emulsifier may be used regardless of the type of oil droplets,thus also allowing for coexistence and mixture of emulsions withdifferent types of oil agents.

Moreover, in the conventional emulsification method, because the oildroplets form microemulsions, a large amount of the surfactant wasrequired, while in the three-phase emulsification method, emulsificationwas possible using only a low concentration of emulsificationdispersant.

Additionally, in the three-phase emulsions described above, 1) a stableformation of large oil drops shaped like salmon roe is possible, 2) asfor the creaming state being dependent on the difference in specificgravity, the emulsified state showed no difference even when theseparated phase was removed, and 3) it was possible to form emulsionseven with the addition of additives into the aqueous phase or into theoil phase of the three-phase emulsification.

Hereinafter, an embodiment wherein the emulsification dispersantrealizing the three-phase emulsification described above is applied toemulsion fuels is described. The emulsion fuels in the present inventioncontain said emulsification dispersant as the essential component in thefuels: water-added oils; e.g. light oil, heavy oil (heavy oil A, heavyoil C), high viscosity heavy oil, kerosene, or gasoline, etc.

Herein, the preferred average particle size of the vesicles formed froman amphiphilic substance is 8 nm to 500 nm. A particle size smaller than8 nm reduces the attractive force attributed to the van der Waals force,and then the vesicles may not adhere onto the surface of the oil,whereas, if the particle size is larger than 500 nm, stable emulsionscannot be maintained as previously described.

In order to maintain the particle size of the vesicles within this rangewhile an emulsion is being formed, a range of 200 nm to 800 nm isacceptable for conditioning of the dispersant. Such particles size foremulsifier was due to a reason because the vesicles are processed intofine particles during the emulsion formation process.

For the amphiphilic substance forming such vesicles,polyoxylene-hydrogenated caster oil derivatives represented by thegeneral formula (Formula 4) are to be used.

For hydrogenated caster oil derivatives, derivatives with an averagenumber of 5 to 15 added ethylene oxide molecules (E) may be used.Furthermore, in order to enhance the thermal stability of said vesiclesdepending on the purpose, other ionic surfactants, amphotericsurfactants or other nonionic surfactants may be used together with saidemulsification dispersant.

Moreover, for the method of producing emulsion fuels described above,particularly with high viscosity heavy oil, temperature control iscrucial. That is, for emulsion fuels in which high viscosity oils suchas heavy oil, etc. are used, processes are required for conditioning thefluidization (step IV), and for adjusting the temperature in order toreduce the temperature of the fluidity-conditioned high viscosity oil tothe designated temperature (below 60° C.) (step V).

As shown in FIG. 8, a process for conditioning the fluidization (stepIV) is achievable by: a process for thermally adjusting the temperatureto approximately 80° C. so as to permit fluidization of the crude oil(step IV-1), followed by a process for adding a required amount of oilof which the viscosity is to be conditioned (step IV-2), and a processfor homogenization by stirring (step IV-3). The viscosity duringhomogenization is controllable depending on the amount of oil to beadded. Moreover, the temperature to be reached during the temperatureadjustment in step IV-1 does not necessarily have to be 80° C., providedit is mixable with the oil; however when using high viscosity oils suchas heavy oils, etc., the temperature must be reduced down toapproximately 60° C. or below when mixing with the emulsificationdispersant. Therefore, when using high viscosity oils, after the processof fluidity-conditioning, a process for temperature adjustment (step V)is required to reduce the temperature of the fluidity-conditioned crudeoil to the designated temperature (below 60° C.). The processes in stepIV and step V may be omitted depending on the crude oil used.

Subsequently, the emulsion fuel is generated after a process of addingthe crude oil to be fluidized into the emulsification dispersant liquid(step VI) and a process of stirring for process the particles into fineparticles (step VII). That is, the gradual addition of a small amount offluidity-conditioned heavy oil or light oil, etc., into water and anemulsification dispersant for the emulsion fuel composition, afterhaving been stirred, results in creation of the emulsion fuel. A highspeed of stirring (up to 16000 rpm, in lab.) is preferred; however, anystirring speed is acceptable as long as an increase in temperature isnot observed. It is also preferable to perform the process of addinginto the water and the process of processing the particles into fineparticles at the same time.

Embodiment 11

Hereinafter, an embodiment is described wherein emulsion fuels areformed, along with the emulsification of water and light oil or heavyoil A, using an emulsification dispersant comprising as the maincomponent vesicles formed from an amphiphilic substance.

An attempt was made to emulsify a commercially produced light oil, and aheavy oil A using regular tap water. For the emulsification dispersant,among polyoxyethylene-hydrogenated caster oil derivatives forminghydrophilic nanoparticles, a dispersion was used wherein a derivativewith an average number of 10 added ethylene oxide (EO) molecules (fromhereon HCO-10; molecular weight 1380 g/mol) was dispersed with water. Aspreviously described, HCO-10 is known to be hardly soluble in water andforms vesicles by assembling themselves in water, as shown in Table 2,and although the average particle size depends on the concentration, atthe stage of aqueous dispersion, the size is 200 nm to 800 nm.Considering the stability of the dispersion, the concentration was setwithin a range of 5 to 20 wt %. No surfactant was used.

As for the emulsifying machine, a conventional homogenizer was used, andas for the combustion, a combustion device with a burner designated forkerosene was used, and the five components (NO, CO, SO₂, CO₂, and O₂) ofcombustion exhaust gases were monitored automatically.

A fuel was added to the HCO-10 aqueous dispersion and stirred for tenminutes by the homogenizer at 16000 rpm to prepare the emulsion. Thecomposition of the emulsion in a weight ratio is HCO-10 at 5 wt %, oilphase at 50 wt %, and water at 45 wt %.

In FIGS. 9A and 9B, after forming the emulsions of light oil and heavyoil A using a conventional surfactant and the emulsions of light oil andheavy oil A using the three-phase emulsification method of the presentinvention, the results are shown for the state of the emulsion using thesurfactant two days later, and for the state of the emulsion using thethree-phase emulsification method thirty days later (the state remainedthe same after two months). As seen from the figure, the emulsion usingthe conventional surfactant showed a complete phase separation, whereasthe emulsion using the three-phase emulsification method remainedextremely stable over time, even without the use of additives other thanthe HCO-10 emulsification dispersant.

Furthermore, after changing the weight ratio of HCO-10, oil phases(heavy oil A, light oil) and water, and stirring to regulate theemulsions, the states of one week after and one month after wereobserved in room temperature.

Examples of emulsification with heavy oil A is shown in Table 17 throughTable 19. Furthermore, the photographs representing the emulsifiedstates in Table 18 are shown in FIG. 10. In the short term, emulsionswere formed with the HCO-10 at 0.5 wt % and the oil phase at 95 wt %;however, when the oil phase exceeded 80 wt %, changes in the timedependence were observed.

TABLE 17 Examples (1) of Heavy oil A emulsification using 10 wt % HCO-10aqueous dispersion No. 1 2 3 4 5 6 7 8 9 10 HCO-10 9 8 7 6 5 4 3 2 1 0.5Water 81 72 63 54 45 36 27 18 9 4.5 Heavy oil A 10 20 30 40 50 60 70 8090 95 Emulsification ◯ ◯ ◯ ◯ ◯ ◯ Δ Δ Δ Δ stability (7 days/roomtemperature) Emulsification ◯ ◯ ◯◯ ◯ ◯ ◯ Δ X X X stability (1 month/roomtemperature) Emulsified (1) (2) (3) state ◯: No phase separation, Δ:Separated due to the difference in specific gravity (coacervation), X:Separated (1): O/W type emulsion, (2): W/O type emulsion, (3): W/Omicroemulsion Figures are shown in wt %.

TABLE 18 Examples (2) of heavy oil A emulsification using 15 wt % HCO-10aqueous dispersion No. 1 2 3 4 5 6 7 8 9 10 11 HCO-10 14.3 13.5 12 10.59 7.5 6 4.5 3 1.5 0.75 Water 80.8 76.5 68 59.5 51 42.5 34 25.5 17 8.54.25 Heavy Oil A 5 10 20 30 40 50 60 70 80 90 95 Emulsificationstability (7 ◯ ◯ ◯ ◯ ◯ ◯ ◯ Δ Δ Δ Δ days/room temperature) Emulsificationstability ◯ ◯ ◯ ◯ ◯ ◯ ◯ Δ X X X (1 month/room temperature) Emulsifiedstate (1) (2) (3) ◯: No phase separation, Δ: Separated due to thedifference in specific gravity (coacervation), X: Separated (1): O/Wtype emulsion, (2): W/O type emulsion, (3): W/O microemulsion Figuresare shown in wt %.

TABLE 19 Examples (3) of Heavy oil A emulsification at variousconcentrations of HCO-10 Emulsified HCO-10 Heavy state ConcentrationWater oil A After 1 day After 20 days 0.1 39.9 60 ◯ Δ 0.2 39.8 60 ◯ Δ0.4 39.6 60 ◯ Δ 0.6 39.4 60 ◯ ◯ 0.8 39.2 60 ◯ ◯ 1 39 60 ◯ ◯ 2 38 60 ◯ ◯4 36 60 ◯ ◯ 6 34 60 ◯ ◯ 10 30 60 ◯ ◯ ◯: No phase separation, Δ:Separated due to the difference in specific gravity (coacervation)Figures are shown in wt %.

As seen from the above results, a composition comprised of HCO-10 at0.1-14.25 wt %, heavy oil A at 5-95 wt % and the correspondingproportion of water, and preferably a composition comprised of HCO-10 at5-14.25 wt %, heavy oil A at 5-60 wt % and the corresponding proportionof water are recommended.

Emulsification examples with light oil are shown in Table 20 throughTable 23. In addition, photographs representing the emulsified states ofTable 22 are shown in FIG. 11, and photographs representing theemulsified states of Table 23 are shown in FIG. 12. In these case, withthe oil phase exceeds 80 wt %, a stable emulsion could not be formed.However, no changes were observed over time.

TABLE 20 Example (1) of light oil emulsification with 10 wt % HCO-10aqueous dispersion No. 1 2 3 4 5 6 7 8 9 10 HCO-10 9 8 7 6 5 4 3 2 1 0.5Water 81 72 63 54 45 36 27 18 9 4.5 Light oil 10 20 30 40 50 60 70 80 9095 Emulsification ◯ ◯ ◯ ◯ ◯ ◯ Δ X X X stability (7 days/roomtemperature) Emulsification ◯ ◯ ◯ ◯ ◯ ◯ Δ X X X stability (90 days/roomtemperature) Emulsified (1) (2) (3) state ◯: No phase separation, Δ:Separated due to the difference in specific gravity (coacervation), X:Separated (1): O/W type emulsion, (2): W/O type emulsion, (3): W/O microemulsion and separated aqueous phase Figures are shown in wt %.

TABLE 21 Example (2) of light oil emulsification with 10 wt % HCO-10aqueous dispersion No. 1 2 3 4 5 6 7 8 9 HCO-10 4.5 4 3.5 3 2.5 2 1.5 10.5 Water 85.5 76 66.5 57 47.5 38 28.5 19 9.5 Light oil 10 20 30 40 5060 70 80 90 Emulsification ◯ ◯ ◯ ◯ ◯ ◯ X X X stability (7 days/roomtemperature) Emulsification ◯ ◯ ◯ ◯ ◯ ◯ X X X stability (90 days/roomtemperature) Emulsified (1) (3) state ◯: No phase separation, Δ:Separated due to the difference in specific gravity (coacervation), X:Separated (1): O/W type emulsion, (3): W/O micro emulsion and separatedaqueous phase Figures are shown in wt %.

TABLE 22 Example (5) of light oil emulsification with 10 wt % HCO-10aqueous dispersion No. 1 2 3 4 5 6 7 8 9 10 11 HCO-10 0.95 0.9 0.8 0.70.6 0.5 0.4 0.3 0.2 0.1 0.05 Water 94.1 89.1 79.2 69.3 59.4 45.5 39.429.7 19.8 9.9 4.95 Light oil 5 10 20 30 40 50 60 70 80 90 95Emulsification stability ◯ ◯ ◯ Δ Δ Δ Δ X X X X (7 days/room temperature)Emulsification stability ◯ ◯ ◯ Δ Δ Δ Δ X X X X (90 days/roomtemperature) Emulsified state (1) (2) (3) ◯: No phase separation, Δ:Separated due to the difference in specific gravity (coacervation), X:Separated (1): O/W type emulsion, (2): W/O type emulsion, (3): W/O microemulsion and separated aqueous phase Figures are shown in wt %.

TABLE 23 Example (4) of light oil emulsification at variousconcentrations of HCO-10. HCO-10 Concentration Water Light oilEmulsified state 0.5 49.5 50 Δ 1 49 50 Δ 2.5 47.5 50 ◯ 5 45 50 ◯ 10 4050 ◯ ◯: No phase separation, Δ: Separated due to the difference inspecific gravity (coacervation) Figures are shown in wt %.

As shown by the above results, a composition consisting of HCO-10 at0.4-10.0 wt %, light oil at 5-95 wt % and the corresponding proportionof water, and preferably a composition consisting of HCO-10 at 0.8-10.0wt %, light oil at 5-60 wt %, and the corresponding proportion of waterare recommended.

In the examples so far, cases were shown using light oil and heavy oilA; furthermore, in the examples of emulsification with gasoline,kerosene, and heavy oil C, as shown in Table 24, stable emulsifiedstates have also been observed using a small amount of emulsificationdispersant.

TABLE 24 Examples of the emulsified state according to different oils.Emulsified Oil type HCO-10 Water state Gasoline 5 45 ◯ kerosene 5 45 ◯Heavy oil C 5 45 ◯ Figures are in wt %. Oil content is 50 wt %.

An emulsification with high viscosity heavy oil has to go through aviscosity-conditioning process. As for the viscosity-conditioning agentto be used therein, light oil, low viscosity oil obtained as adistillate from the oil refining process, or heavy oil A is preferred;however, as long as homogeneously mixable with high viscosity heavy oil,oil type need not be particularly limited.

In Table 25 and in FIG. 13, the results of the viscosity conditioningusing petroleum, light oil, Heavy oil A, and liquid paraffin are shown.

TABLE 25 Viscosity of each type of conditioned heavy oil Viscosity ofheavy oil conditioned with kerosene kerosene 10 20 30 40 50 60 70 80 90Residue oil 90 80 70 60 50 40 30 20 10 Viscosity (mPs) — 33383 2250 341122 76 65 61 61 Viscosity of heavy oil conditioned with light oil Lightoil 10 20 30 40 50 60 70 80 90 Residue oil 90 80 70 60 50 40 30 20 10Viscosity(mPs) — 98980 7005 922 230 112 71 61 61 Viscosity of heavy oilconditioned with heavy oil A Heavy oil A 10 20 30 40 50 60 70 80 90Residue oil 90 80 70 60 50 40 30 20 10 Viscosity(mPs) — 16900 6536 1794317 147 92 75 66 Viscosity of heavy oil conditioned with liquid paraffinLiquid paraffin 10 20 30 40 50 60 70 80 90 Residue oil 90 80 70 60 50 4030 20 10 Viscosity(mPs) — — — 95064 19788 10384 1461 849 339 —:immeasurable (20° C., B-type viscometer, Rotor No. 3 is used)

In FIG. 13, up to approx. 30,000 mPs does not cause a handling problemin the next process. As for an emulsification example in which 40 wt %of liquid paraffin was used as the viscosity-conditioning agent,although the emulsification itself was possible, subsequent handling wasdifficult due to unfavorable fluidity.

Furthermore, results of the emulsifications of a conditioned heavy oilusing heavy oil A added at 30 wt % as a viscosity conditioning agent and10 wt % HCO-10 aqueous dispersion are shown in Table 26 and Table 27.

TABLE 26 An emulsification example of conditioned heavy oil (Heavy oil A30 wt %) with 10 wt % HCO-10 dispersion No. 1 2 3 4 5 6 7 8 9 10 HCO-109 8 7 6 5 4 3 2 1 0.5 Water 81 72 63 54 45 36 27 18 9 4.5 Conditioned 1020 30 40 50 60 70 80 90 95 heavy oil Emulsification ◯ ◯ ◯ ◯ ◯ ◯ ◯ Δ X Xstability(1 month/room temperature) ◯: No phase separation, Δ: Separateddue to the difference in specific gravity (coacervation), X: SeparatedFigures are shown in wt %

TABLE 27 An emulsification example of conditioned heavy oil with variousconcentration of HCO-10. HCO-10 Conditioned Emulsified ConcentrationWater heavy oil state 0.5 49.5 50 ◯ 1 49 50 ◯ 2.5 47.5 50 ◯ 5 45 50 ◯0.3 29.7 70 ◯ 1.5 28.5 70 ◯ 3 27 70 ◯ ◯: No phase separation, Δ:Separated due to the difference in specific gravity (coacervation)Viscosity conditioning agent: heavy oil A, Heavy oil A/high viscosityheavy oil wt ratio = 3/7 Figures are shown in wt %.

In addition, examples of emulsification experiments wherein petroleum,light oil, and liquid paraffin were used as viscosity-conditioningagents are shown in Table 28, Table 29, and Table 30.

TABLE 28 Emulsification example (1) of each type of conditioned heavyoil with 10 wt % HCO-10 dispersion. Oil type Liquid kerosene/ Light oil/Heavy oil A/ paraffin/ heavy oil heavy oil heavy oil heavy oil Viscosity30/70 30/70 30/70 40/60 conditioning agent/ Heavy oil Conditioned 50 5050 50 heavy oil Water 45 45 45 45 HCO-10  5  5  5  5 Emulsification ◯ ◯◯ Δ stability (1 month/room temperature) ◯: No phase separation (goodfluidity) Δ: No phase separation (fluidity defect) Figures are shown inwt %.

TABLE 29 Emulsification example (2) of each type of conditioned heavyoil with 10 wt % HCO-10 dispersion. Oil type Liquid kerosene/ Light oil/Heavy oil A/ paraffin/ heavy oil heavy oil heavy oil heavy oil Viscosity30/70 30/70 30/70 40/60 conditioning agent/ Heavy oil Conditioned 70 7070 70 heavy oil Water 27 27 27 27 HCO-10  3  3  3  3 Emulsification ◯ ◯◯ Δ stability (1 month/room temperature) ◯: No phase separation (goodfluidity) Δ: No phase separation (fluidity defect) Figures are shown inwt %.

TABLE 30 Emulsification example (3) of each type of conditioned heavyoil with 10 wt % HCO-10 dispersion. Oil type kerosene/heavy Light oil/Heavy oil A/ oil heavy oil heavy oil Viscosity 50/50 50/50 50/50conditioning agent/Heavy oil Conditioned 70 70 70 heavy oil Water 27 2727 HCO-10  3  3  3 Emulsification ◯ ◯ ◯ stability (1 month/roomtemperature) ◯: No phase separation (good fluidity) Δ: No phaseseparation (fluidity defect) Figures are shown in wt %.

As shown by the above results, a composition consisting of HCO-10 at0.3-9 wt %, conditioned heavy oil at 80-10 wt % and the correspondingproportion of water, and preferably a composition consisting of HCO-10at 0.3-9 wt %, conditioned heavy oil at 70-30 wt+% and the correspondingproportion of water are recommended.

Combustion experiments using a light oil emulsion and a heavy oil Aemulsion were individually conducted. Using a combustion devicespecifically designated for kerosene, without modifying the burner, theemulsion fuels were completely burnt without extinguishing.

The results of the measurement of exhaust gases from the light oilcombustion are shown in FIG. 14, and the results of the measurement ofexhaust gases from the heavy oil A combustion are shown in FIG. 15.

As shown by FIG. 14, when the fuel was changed from light oil toemulsion, the NOx concentration in the exhaust gases was significantlyreduced, and became approximately 1/10 of the regular concentration fornormal fuel once the combustion was stabilized. Furthermore, althoughthe CO concentration was previously increased, a tendency towardreduction was observed along with the SO₂ concentration. On thecontrary, the oxygen concentration in the exhaust gases increased, andthe CO₂ concentration also increased even taking account thatconsidering that the fuel component was 50 wt %. Therefore, thecombustion is deemed to be more complete than a fuel solely comprised oflight oil. The combustion temperature of the light oil and the emulsionwas approx. 1150° C. and 950° C., respectively, a decrease ofapproximately 200° C.

In addition, as clearly shown by FIG. 15, when the fuel change occurredfrom heavy oil A to emulsion, the NOx concentration in the exhaust gaswas significantly reduced, and became approximately ⅙ of the regularconcentration of normal fuel once the combustion was stabilized.Although the CO concentration was previously increased, a tendencytoward reduction was observed along with the SO₂ concentration. On thecontrary, the oxygen concentration in the exhaust gases increased, andthe CO₂ concentration also increased even taking account thatconsidering that the fuel component was 50 wt %. Therefore, thecombustion is deemed to be more complete than a fuel solely comprised ofheavy oil A. The combustion temperature of the Heavy oil A and theemulsion was approx. 1050° C. and 900° C., respectively, a decrease ofapproximately 150° C.

Hence, by using the emulsion fuels described above, it is expected thatair pollution can be significantly decreased, and thus reducing theadverse effects on the environment.

INDUSTRIAL APPLICATION

The invention is applicable to functional oil-based agents such ascosmetics, medical products, food products, agrichemicals, fuelemulsions, soil conditioners, etc, or applicable to emulsifiedpreparations in which granule particles have been emulsified anddispersed, and also applicable to uses involving dispersions, etc.

What is claimed is:
 1. An emulsion fuel comprising: a dispersant solution comprising an amphiphilic substance capable of forming vesicles; and diesel oil droplets or fuel oil droplets; wherein the vesicles are adhered onto a surface of the diesel oil droplets or the fuel oil droplets thereby forming the emulsion fuel, the average particle size of said vesicles being 200 nm-800 nm prior to being adhered and 8 nm-500 nm after being adhered.
 2. An emulsion fuel comprising: a dispersant comprising an amphiphilic substance capable of forming vesicles; heavy oil droplets having an adjusted viscosity; wherein the vesicles are adhered onto a surface of the heavy oil droplets thereby forming the emulsion fuel, the average particle size of said vesicles being 200 nm 800 nm prior to being adhered and 8 nm-500 nm after being adhered.
 3. The emulsion fuel according to claim 1, wherein said amphiphilic substance is a derivative with an average number of 5 to 15 added ethylene oxide molecules (E), selected from among polyoxyethilene hydrogenated caster oil derivatives represented by the following general formula 3


4. The emulsion fuel according to 1, wherein a composition of the emulsion fuel consists of said amphiphilic substance at 0.1-4.5 wt %, said fuel at 5-60 wt % and the corresponding proportion of water.
 5. The emulsion fuel according to claim 2, wherein a composition of the emulsion fuel consists of said amphiphilic substance at 0.3-9.0 wt %, said heavy oil having an adjusted viscosity at 10-80 wt % and the corresponding proportion of water.
 6. A method of forming the emulsion fuel according to claim 1, the method comprising the steps of: forming the dispersant solution wherein the amphiphilic substance capable of forming vesicles spontaneously is dispersed; adjusting the average particle size of said vesicles to be 200 nm-800 nm prior to adhering the vesicles onto a surface of diesel oil droplets or fuel droplets; adhering the vesicles onto the surface; and adjusting the average particle size of said vesicles to 8 nm-500 nm after the vesicles are adhered onto the surface.
 7. A method of forming the emulsion fuel according to claim 2, the method comprising the steps of: forming the dispersant solution wherein the amphiphilic substance capable of forming vesicles spontaneously is dispersed; adjusting the average particle size of said vesicles to be 200 nm-800 nm prior to adhering the vesicles onto a surface of heavy oil droplets; adhering the vesicles onto the surface; and adjusting the average particle size of said vesicles to 8 nm-500 nm after the vesicles are adhered onto the surface. 